1. Field
The present invention relates to a frame of a cab for an agricultural machine, in particular for a tractor, comprising a series of uprights carrying at their tops a structure for supporting the roof.
2. State of the Art
Cab frames for agricultural machines are generally made up of a plurality of metal tubular sectional elements welded together. The tubular sectional elements which form the uprights and the roof-supporting structure must possess characteristics of structural resistance adequate for the mass of the agricultural machine and must be able to resist a crushing force equal to twice the weight of the agricultural machine. At the same time, it is desirable that the metal tubular sectional elements making up the uprights should enable the glazed surfaces of the cab to be set as close to one another as possible in order to increase visibility and to obtain a better result from the aesthetic point of view. The tubular sectional elements making up the roof-supporting structure must moreover have a very limited height in order not to reduce visibility or reduce the opening for access through the doors. In addition, the tubular sectional elements making up the uprights and the roof-supporting structure must be provided with resting surfaces for the weather-stripping of the doors, windscreen and the rear window. The resting surfaces must have an optimized inclination according to the position of the sectional element so as to guarantee a condition of optimal seal with the corresponding weather-stripping.
In known solutions, to meet the above requirements, frequently tubular sectional elements are used having different cross sections according to their position. This solution is costly from the standpoint of the production process in that it involves managing tubular sectional elements of varying cross section.
The aim of the present invention is to provide a frame of a cab for an agricultural machine that makes it possible to overcome the above-mentioned problems.
A frame for a cab for an agricultural machine includes a plurality of uprights which carry at their upper region a structure for supporting the roof. The plurality of uprights is formed of a first series of sectional elements having cross sections which are equal to one another. The structure for supporting the roof is formed by a second series of sectional elements having cross sections which are equal to one another.
In one embodiment of the invention, each of the sectional elements of the first series has a cross-section formed of two parallel rectilinear sides, an arched portion and two inclined sides having outer surfaces for resting weather-stripping.
In a second embodiment, each of the sectional elements of the second series has a trapezoidal cross section with a pair of rectilinear sides oriented parallel to one another and a pair of inclined sides.